Answer:
Nullification, in United States constitutional history, is a legal theory that helps to nullify, or invalidate, any federal laws which that state has deemed unconstitutional with respect to the United States Constitution.
Here are some of the weapons first used in WWI. Airplanes, Derigables, poison gas, flamethrower, and tanks. Other weapons that were invented before the war but not used on a wide scale or were not reliable until WWI were the machine gun, submarines, torpedoes, small mortars and very large caliber artillery. WWI also saw the use of the radio for the first time in combat conditions.
